Inform the guest introspection tool that a breakpoint instruction (INT3)
is being executed. These one-byte intructions are placed in the slack
space of various functions and used as notification for when the OS or
an application has reached a certain state or is trying to perform a
certain operation (like creating a process).
Signed-off-by: Mihai Donțu <mdontu@xxxxxxxxxxxxxxx>
Signed-off-by: Nicușor Cîțu <ncitu@xxxxxxxxxxxxxxx>
---
arch/x86/kvm/svm.c | 4 ++++
arch/x86/kvm/vmx.c | 15 +++++++++++----
arch/x86/kvm/x86.c | 7 +++++++
3 files changed, 22 insertions(+), 4 deletions(-)
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index d6c7680e224b..17902a9e518d 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -2721,6 +2721,10 @@ static int bp_interception(struct vcpu_svm *svm)
{
struct kvm_run *kvm_run = svm->vcpu.run;
+ if (!kvmi_breakpoint_event(&svm->vcpu,
+ svm->vmcb->save.cs.base + svm->vmcb->save.rip))
+ return 1;
+
kvm_run->exit_reason = KVM_EXIT_DEBUG;
kvm_run->debug.arch.pc = svm->vmcb->save.cs.base + svm->vmcb->save.rip;
kvm_run->debug.arch.exception = BP_VECTOR;
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index fd92267a7a65..72d4b521fed7 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -7088,7 +7088,7 @@ static int handle_exception(struct kvm_vcpu *vcpu)
struct vcpu_vmx *vmx = to_vmx(vcpu);
struct kvm_run *kvm_run = vcpu->run;
u32 intr_info, ex_no, error_code;
- unsigned long cr2, rip, dr6;
+ unsigned long cr2, dr6;
u32 vect_info;
enum emulation_result er;
@@ -7166,7 +7166,10 @@ static int handle_exception(struct kvm_vcpu *vcpu)
kvm_run->debug.arch.dr6 = dr6 | DR6_FIXED_1;
kvm_run->debug.arch.dr7 = vmcs_readl(GUEST_DR7);
/* fall through */
- case BP_VECTOR:
+ case BP_VECTOR: {
+ unsigned long gva = vmcs_readl(GUEST_CS_BASE) +
+ kvm_rip_read(vcpu);
+
/*
* Update instruction length as we may reinject #BP from
* user space while in guest debugging mode. Reading it for
@@ -7174,11 +7177,15 @@ static int handle_exception(struct kvm_vcpu *vcpu)
*/
vmx->vcpu.arch.event_exit_inst_len =
vmcs_read32(VM_EXIT_INSTRUCTION_LEN);
+
+ if (!kvmi_breakpoint_event(vcpu, gva))
+ return 1;
+
kvm_run->exit_reason = KVM_EXIT_DEBUG;
- rip = kvm_rip_read(vcpu);
- kvm_run->debug.arch.pc = vmcs_readl(GUEST_CS_BASE) + rip;
+ kvm_run->debug.arch.pc = gva;
kvm_run->debug.arch.exception = ex_no;
break;
+ }
default:
kvm_run->exit_reason = KVM_EXIT_EXCEPTION;
kvm_run->ex.exception = ex_no;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 6ab052fdb786..b1cbcf44cf70 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -8546,6 +8546,13 @@ int kvm_arch_vcpu_set_guest_debug(struct kvm_vcpu *vcpu,
kvm_queue_exception(vcpu, BP_VECTOR);
}
+#ifdef CONFIG_KVM_INTROSPECTION
+ if (kvmi_bp_intercepted(vcpu, dbg->control)) {
+ ret = -EBUSY;
+ goto out;
+ }
+#endif
+
/*
* Read rflags as long as potentially injected trace flags are still
* filtered out.
